Anibacterial, antibiofilm and antioxidant activity of Potamogeton nodosus Poir. extracts

Antibacterial, antibiofilm and antioxidant activity of acetone, ethanol, ethyl acetate and diethyl ether extracts of P. nodosus Poir. were tested. In vitro antibacterial activity was investigated by microdilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) have been determined. The values were in the range from 5 to > 5 mg/ml. Antibiofilm activity was tested by crystal violet assay. The biofilm inhibitory concentration (BIC) values were from 2.03 to > 10 mg/ml. The best results against biofilm formation had ethanol and ethyl acetate extracts. The total phenolic content was established by using Folin-Ciocalteu method. The highest total phenol content was found in the ethyl acetate extract (28.45 mg GA/g) while the lowest content in the ethanol extract (22.74 mg GA/g). The concentrations of flavonoids were determined using aluminium chloride method. The concentration of total flavonoid content was 102.09 mg RU/g for the ethyl acetate extract, while the lowest content was noticed in diethyl ether extract (32.93 mg RU/g). The antioxidant activity was determined by the DPPH free radicals assay. Antioxidative efficiency was in the range from 641.77 to 8811.63 μg/ml. The tested extracts showed weak antioxidant activity (AAI < 0.5).